1. Field of the Invention
The present invention relates generally to a gas lighter and, more particularly, to a gas lighter capable of maintaining a continuous combustion by ensuring a diffusion flame in the form of an ordinary reddish yellow visible flame which is not to be extinguished under the influence of the wind or the like.
2. Description of the Related Arts
A diffusion flame is in general used as a flame for a gas lighter. The diffusion flame inconveniently has a poor wind resistance and, for outdoor use especially, may present unstable lighting and burning properties. Thus, in view of the wind resistance, there has been recently developed a mechanism in which a premix gas is ignited and burned within a combustion cylinder.
However, a premix flame obtained by burning the premix gas is in the state of a complete combustion, whose color is a pale blue white, making it difficult to visually confirm the state of combustion in a light place under, e.g., daylight. In order to compensate for such state and reignite the gas in case of extinction due to the wind or the like, there has also been developed a technique in which a metal wire or catalytic member is mounted on the opening of the combustion cylinder to maintain a red heating state. Such red heated metal wire or catalytic member merely shows the presence of a combustion within the interior of the combustion cylinder, but does not exhibit any confirmation of the size of the flame exposed from the opening of the combustion cylinder upon igniting the object to be lit, in other words, the ejection amount of the gas mixture for producing a combustion criticality.
With the aim of ensuring easy visual confirmation of a combustion criticality of the premix flame, there has also been developed a mechanism in which a fuel gas ejected from the fuel tank is caused to diverge to form a second fuel gas ejection flow passage whose leading edge is introduced into the interior of the combustion cylinder. In this case, also, due to some factors such as size of the combustion cylinder or mutual variation in ejection amounts of the premixed gases subjected to a complete combustion and of the fuel gas for producing a diffusion flame through the ejection from the second fuel gas ejection flow passage, the fuel gas ejected from the second fuel gas ejection flow passage may not be allowed to form a diffusion flame, which results in an assimilation with the premix flame to be produced within the combustion cylinder. Thus, unstable factors disadvantageously remain intact.
In order to obtain the premixed gas, within a flow passage for a fuel gas there must be arranged a nozzle hole (orifice) for increasing a jet flow rate for the fuel gas and for sucking the ambient air by its negative pressure. On the contrary, there must be controlled a gas ejection amount of a second fuel gas ejection flow passage and a gas flow ejected from the nozzle hole to obtain a premixed gas so as to present a mutually balancing combustion. To balance the mutual combustion, there is further disposed a second nozzle hole (orifice) for controlling the gas ejection amount in the middle of the second gas ejection flow passage, thereby obtaining a combustion flame which is useful for igniting objects to be lit and is not influenced by the wind or the like.
However, in order to controllably balance the ejection amounts of the fuel gas, it is required to construct the mutual nozzle holes (orifices) at a very minute machining accuracy in microns, which will actually be extremely difficult. Moreover, there is inevitably a structural difference in flow passage resistance between the fuel gas ejection flow passage for producing a premix flame and the fuel gas ejection passage for producing a diffusion flame, which structural difference will result in a difference in the gas ejection pressure. This means that it is difficult to obtain an ideal mutual combustion condition even if the two nozzle holes are numerically well balanced.
In the conventional gas lighter, a catalytic member is attached to the opening of a combustion cylinder for the confirmation of combustion or reigniting operation. A red heating of the catalytic member in the initial ignition arises from a combustion heat of the gas mixture within the combustion cylinder. When a combustion flame is distinguished due to any phenomena, continuously ejecting mixed gas will react with the catalytic member to generate a reaction heat which in turn causes a regeneration of the premix flame in the exterior of the combustion cylinder. In this conventional gas lighter, the premixed gas has its combustion base located at a deeper point within the combustion cylinder in the combustion condition at the time of initial ignition, and the catalytic member provided on the opening of the combustion cylinder is not allowed to react. Thus, the premix flame may be forced to jet up to the outside of the opening of the combustion cylinder in such a manner that the diffusion flame which is a visible flame is assimilated with the premix flame, which leads to an unclear combustion criticality of the diffusion flame.